The use of laser generated beam projectors in vehicle measurement systems has been known. Devices, such as this Assignee's LAZER ALIGNER (TM) marketed by Kansas Jack Division of Hain-Werner Corporation, are disclosed in several measurement system patents such as U.S. Pat. Nos. 4,330,945, 4,338,027 and 4,454,659 (all assigned to Hein-Werner Corporation). The use of such laser projector in a measurement system was further refined by this Applicant's U.S. Pat. No. 4,578,870 for a selectible beam/plane projecting laser. Such laser is also used by this Assignee in the above mentioned LAZER ALIGNER (TM) and related products.
In all of the above mentioned products, the laser projector is powered by an alternating current with a power cord connection from the laser projector to a convenient power outlet. The laser projector, because of its size to accomodate the alternating current technology, cannot pivot 360.degree. about its mounting axis. The power cord causes an obstruction. This requires an operator of a vehicle measuring system to dismount the laser projector, rotate the laser projector 180.degree. and remount the laser projector to the measuring system support member during the measurement of a vehicle's front and back ends as disclosed in Eck U.S. Pat. Nos. 4,330,945 and 4,454,659. Such removal and remounting of the laser projector necessitates a recalibration and realignment of the laser projector with respect to the vehicle measurement datum plane. That operation potentially introduces errors into the measurement procedure as well as adds time and inefficiencies to the vehicle measurement procedure.
Another problem with the prior art laser projector is the size and weight of the unit. The units are bulky and heavy resulting in mounting support members to be of sufficient size and strength to support such laser projector units. Such requirements add costs and inefficiencies to the overall measurement system.
An additional problem with the prior art laser measurement system is that the mounting of the laser on the support member is not on the same axis as the pivot point of the mounting support. The size and weight of the lazer projector as well as the power cord connection contribute to this off-axis condition. Such condition limits the effective range of use of the laser projector and usually requires a realignment and recalibration of the laser projector to the vehicle datum plane.